Ford Motor Co is lowering mileage estimates on six of its models, including a number of hybrids, and says it will reimburse owners for the difference.

The No. 2 U.S. automaker said the ratings would be cut on its 2013 and 2014 model year hybrid and plug-in hybrid vehicles as well as most 2014 Fiesta cars. It was the second time Ford cut fuel ratings for the C-Max hybrid in under a year, Reuters reports.

"We apologize to our customers and will provide goodwill payments to affected owners," Ford CEO Alan Mulally said. in a statement. "We also are taking steps to improve our processes and prevent issues like this from happening again."

Unfortunately, the restatement of mileage estimates is nothing new in the auto industry.

Last August, Ford - which has touted its superior fuel efficiency in the past - cut the ratings for the C-Max hybrid by up to 7 miles per gallon following complaints from consumers and experts that the model's actual mileage fell short of claims.

In 2012, an investigation by the U.S. Environmental Protection Agency showed that both Hyundai and Kia overstated fuel economy by at least a mile per gallon. The South Korean carmakers last December agreed to pay $395 million to settle lawsuits related to the matter.

"Ford isn't the first manufacturer to admit that it was optimistic in its EPA fuel economy ratings, and it might not be the last," said Jack R. Nerad, editorial director at Kelley Blue Book's KBB.com.

In the latest case, Ford said it identified an error through internal testing and notified the U.S. environmental regulator. No adjustments on other vehicles are planned after review of the entire lineup, the company said.

The EPA said it conducted independent tests to confirm Ford's results and ordered the company to correct fuel economy labels on the cars within 15 days.

Ford estimated about 200,000 of the affected vehicles had been sold or leased in the United States, and affected owners would receive a "goodwill payment" of up to $1,050 for the estimated difference in fuel costs. Cars in dealer lots will be relabeled with new window stickers reflecting the corrected estimates.

The largest change is for Ford's Lincoln MKZ hybrid, which saw its combined city and highway fuel economy value reduced by 7 miles per gallon. Other affected models include four versions of the Fiesta, the hybrid and Energi versions of the Fusion, and the C-Max hybrid and Energi.

Is anyone shocked? NHTSA lets them calculate their own numbers and checks less than 1%. They are bogus numbers anyway, they don't reflect real world driving and companies build to make the numbers look good, not for real economy.

Easy to confuse the vague government regulations. EPA fuel econ is just for comparison only as stated on all the stickers. Not based on real world. plus every time EPA changes the requirements there is room for new errors. The gov only gives guidance on calculations for the road HP used in the dyno testing.